Enamel safe cleaning process

ABSTRACT

The present invention describes a process of cleaning an enamel surface with a liquid acidic composition comprising an enamel safe acid wherein the pK a  of said acid is 3.5 or higher, with the proviso that non mono-lower alkyl ethers or phenyl ethers or benzyl ethers of diethylene glycol, wherein the lower alkyl is of 2 to 6 carbon atoms, are present in said composition. The composition employed in said process is safe to enamel.

TECHNICAL FIELD

The present invention relates to a process of cleaning enamel surfaceswith a liquid acidic composition.

BACKGROUND OF THE INVENTION

Compositions for cleaning enamel surfaces are well known in the art.

Liquid compositions having an acidic pH for cleaning enamel surfaceshave been extensively described in the art, especially in hard surfacecleaning application (e.g., bathroom cleaner).

Indeed, it is known to use acidic compositions to clean enamel surfacesas such formulations show good soap scum removal performance andlimescale removal performance. Soap scum and limescale are soils thatfrequently occur on enamel surfaces, especially enamel surfaces locatedin bathrooms, kitchens and the like.

However, there are some limitations to the convenience of acidiccompositions employed as enamel surface cleaner. In particular it isknow, that enamel surfaces are sensitive to acids and may be severelydamaged by acidic compositions used to clean said surfaces.

It is thus and object of the present invention to provide a process ofcleaning enamel surfaces with an acidic composition which is safe tosaid enamel surfaces whilst also exhibiting good cleaning performance ona variety of soils.

It has now been found that the above object is met by a process ofcleaning an enamel surface with a liquid acidic composition comprisingan enamel safe acid.

Advantageously, said process of cleaning enamel surfaces may be used onvarious enamel surfaces. Enamel surfaces can be found in various places,e.g., in households in kitchens (sinks and the like); in bathrooms(tubs, sinks, shower tiles, bathroom enamelware and the like); inwashing machines; and dishes.

A further advantage of the process as described herein is that thecompositions used to clean enamel surfaces show good stain/soil removalperformance.

More particularly, the liquid acidic compositions show good stain/soilremoval performance on various types of stains/soils in particulargreasy soils, e.g., greasy soap scum or greasy soils found in kitchens;limescale; mold; mildew; and other tough stains found on enamelsurfaces.

BACKGROUND ART

U.S. Pat. No. 4,501,680 discloses acidic liquid detergent compositionscomprising mixtures of organic acids, an ether of diethylene glycol anda surfactant.

SUMMARY OF THE INVENTION

The present invention encompasses a process of cleaning an enamelsurface with a liquid acidic composition comprising an enamel safe acidwherein the pK_(a) of said acid is 3.5 or higher; with the proviso thatno mono-lower alkyl ethers or phenyl ethers or benzyl ethers ofdiethylene glycol, wherein the lower alkyl is of 2 to 6 carbon atoms,are present in said composition.

In another preferred embodiment said composition further comprises asurfactant.

The present invention further encompasses the use of an enamel safe acidin a composition to clean an enamel surface wherein the pK_(a) of saidacid is 3.5 or higher and said composition is safe to enamel.

DETAILED DESCRIPTION OF THE INVENTION The Process of Treating aHard-surface

The present invention encompasses a process of treating an enamelsurface with a liquid acidic composition comprising an enamel safe acidas described herein. In a preferred embodiment said acidic liquidcomposition is contacted with said enamel surface.

By “enamel surface” it is meant herein any kind of surface being made ofor coated with enamel.

By “enamel” it is meant titanium or zirconium white enamel or titaniumor zirconium white powder enamel used as a coating for metal (e.g.,steel) surfaces preferably to prevent corrosion of said metal surfaces.

Enamel surfaces can typically be found in: houses: e.g., in bathrooms orin kitchens: e.g., tiles, sinks, showers, shower wash basins, WCs, tubs,sinks, fixtures and fittings and the like. Furthermore, cookware, dishesand the like may have an enamel surface. Enamel surfaces may also befound on household appliances which may be coated with enamel on theirinside and/or outside surface including, but not limited to heatingboiler, washing machines, automatic dryers, refrigerators, freezers,ovens, microwave ovens, dishwashers and so on. Further enamel surfacesmay be found in industrial, architectural and the like applications.Examples of enamel surfaces found in said applications include enamelsurfaces on or in tanks, pipelines, reaction vessels, pumps, chemicalprocessing equipment, mechanical equipment, heat exchangers, hot watertanks, signs, silos or architectural panels.

The process of the present invention provides that the liquid acidiccomposition is applied to the surface to be treated. The composition maybe in its neat form or in its diluted form.

By “diluted form”, it is meant herein that said liquid composition isdiluted by the user typically with water. The composition is dilutedprior to use to a typical dilution level of 10 to 400 times its weightof water, preferably from 10 to 200 and more preferably from 10 to 100.A usually recommended dilution level is a 1.2% dilution of thecomposition in water.

By “in its neat form”, it is to be understood that the liquidcompositions are applied directly onto the enamel surface to be treatedwithout undergoing any dilution, i.e., the liquid compositions hereinare applied onto the hard-surface as described herein.

A preferred process of cleaning an enamel surface according to thepresent invention, is to apply the composition in diluted form withoutrinsing the hard-surface after application in order to obtain goodsoil/stain removal performance.

Another preferred process of treating a enamel surface, is to apply thecomposition, described by the present invention, either in neat ordiluted form, leave it on said surface for a period of time to allow thecomposition to act, optionally wipe said surface with an appropriateinstrument, e.g., a sponge, and then preferably rinse said surface withwater.

The enamel surfaces to be treated may be soiled with a variety of soils,e.g., greasy soils (e.g., greasy soap scum, body grease, kitchen greaseor burnt/sticky food residues typically found in a kitchen and the like)or so called “limescale-containing stains”. By “limescale-containingstains” it is meant herein any pure limescale stains, i.e., any stainscomposed essentially of mineral deposits, as well aslimescale-containing stains, i.e., stains which contain not only mineraldeposits like calcium and/or magnesium carbonate but also soap scum(e.g., calcium stearate) and other grease (e.g. body grease).

Cleaning Performance Test Method

The dilute cleaning performance may be evaluated by the following testmethod: tiles of enamel are prepared by applying to them arepresentative grease/particulate artificial soil followed by ageing.The test compositions and the reference composition are diluted (e.g.,composition:water 1:50 or 1:100), applied to a sponge, and used to cleanthe tiles with a Sheen scrub tester. The number. of strokes required toclean to 100% clean is recorded. The result, i.e., number of strokes, ofthe test composition is compared against the result of the referencecomposition.

The test method for evaluating neat cleaning performance is identical toabove except that the test compositions and reference are used undilutedand that after cleaning a rinsing cycle is performed with clean water.

Greasy Soap Scum Cleaning Performance Test Method

In this test method enamel white tiles (typically 24 cm*4 cm) arecovered with typical greasy soap scum soils mainly based on calciumstearate and artificial body soils commercially available (e.g., 0.3grams with a sprayer). The soiled tiles are then dried in an oven at atemperature of 140° C. for 20 minutes and then aged overnight at roomtemperature (around 20° C.-25° C.). The soiled tiles are then cleanedusing 3 ml of the liquid composition of the present invention poureddirectly onto a Spontex® sponge. The ability of the composition toremove greasy soap scum is measured through the number of strokes neededto perfectly clean the surface. The lower the number of strokes, thehigher the greasy soap scum cleaning ability of the composition.

The Liquid Acidic Composition

The liquid acidic compositions according to the present invention arepreferably, aqueous compositions. Therefore, they may comprise from 70%to 99%, preferably from 75% to 95% and more preferably from 85% to 95%by weight of the total composition of water.

The liquid compositions of the present invention are acidic andtherefore preferably have a pH below 7, preferably from 1 to 6.5, morepreferably from 1 to 5, even more preferably from 2 to 5 and mostpreferably from 2 to 4.

The compositions according to the present invention are advantageouslychemically stable, i.e., there are virtually no chemical reactionsbetween the different ingredients of the compositions, and physicallystable, i.e., that no phase separation occurs when stored in rapid agingtest (RAT), i.e., storage at 50° C. for 10 days.

A proviso of the present invention is that the compositions do notcontain a mono-lower alkyl ether or phenyl ether or benzyl ether ofdiethylene glycol, wherein the lower alkyl is of 2 to 6 carbon atoms.

Enamel Safe Acid

As an essential ingredient the compositions used in a process accordingto the present invention comprise an enamel safe acid as describedherein. Said enamel safe acid has a pK_(a) of 3.5 or higher. Preferablythe pK_(a) of said enamel safe acid is higher than 4.0. More preferablythe pK_(a) of said enamel safe acid is higher than 4.5.

Typically the compositions of the present invention may comprise from0.1% to 10%, preferably from 0.1% to 8% and more preferably from 0.1% to6% by weight of the total composition of said enamel safe acid.

Suitable enamel safe acids having a pK_(a) of 3.5 or higher are organicor inorganic acids having a pK_(a) of 3.5 or higher or mixtures thereof.

Suitable organic acids having a pK_(a) of 3.5 or higher are aromatic oraliphatic organic acids having a pK_(a) of 3.5 or higher or mixturesthereof.

Examples of suitable aliphatic organic enamel safe acids are selectedform the group consisting of: acetic acid; acetoacetic acid; acrylicacid; anisic acid; ascorbic acid; formic acid; glutaric acid; glycolicacid; adipamic acid; adipic acid; anisylpropionic acid; aspartic acid;barbituric acid; butyric acid; caproic acid; β-chlorobutyric acid;γ-chlorobutyric acid; chlorocinnamic. acid; cinnamic acid; crotonicacid; gallic acid; glutaramic acid; heptanoic acid; hexanoic acid;hippuric acid; hydroxybutyric acid; β-hydroxypropionic acid; itaconicacid; mesitylenic acid; methylcinnamic acid; methylglutaric acid;methylsuccinic acid; octanoic acid; pimelic acid; propionic acid;suberic acid; succinic acid; uric acid; and valeric acid; and mixturesthereof.

Examples of suitable aromatic organic enamel safe acids are selectedform the group consisting of o-aminobenzoic acid; m-aminobenzoic acid;p-aminobenzoic acid; benzoic acid; m-brombenzoic acid; m-chlorobenzoicacid; p-chlorobenzoic acid; o-chlorophenylacetic acid;m-chlorophenylacetic acid; p-chlorophenylacetic acid; β-(o-chlorophenyl)propionic acid; β-(m-chlorophenyt) propionic acid; β-(p-chlorophenyl)propionic acid; 3,4-dihydroxybenzoic acid; 3,5-dihydroxybenzoic acid;2,4-dinitrophenol; 3,6-dinitrophenol; diphenylacetic acid;ethylphenylacetic acid; hexahydrobenzoic acid; m-hydroxybenzoic acid;p-hydroxybenzoic acid; α-naphtoic acid; β-naphtoic acid; nitrobenzene;o-nitrophenol; m-nitrophenol; p-nitrophenol; o-nitrophenylacetic acid;m-nitrophenylacetic acid; p-nitrophenylacetic acid;o-β-nitrophenylpropionic acid; p-β-nitrophenylpropionic acid;phenylacetic acid; γ-phenylbutyric acid; α-phenylpropionic acid;β-phenylpropionic acid; m-phthalic acid; p-phthalic acid; o-toluic acid;m-toluic acid; and p-toluic acid; and mixtures thereof.

Examples of suitable inorganic enamel safe acids are selected form thegroup consisting of: o-boric acid; carbonic acid; germanic acid;hydrocyanic acid; hydrogen sulfide; m-silicic acid; o-silicic acid;telluric acid; and tetraboric acid; and mixtures thereof.

Preferably said enamel safe acids having a pK_(a) of 3.5 or higher areorganic or inorganic acids having a pK_(a) of 3.5 or higher or mixturesthereof. More preferably said enamel safe acids having a pK_(a) of 3.5or higher are aromatic or aliphatic organic acids having a pK_(a) of 3.5or higher; or inorganic acids having a pK_(a) of 3.5 or higher; ormixtures thereof.

Preferred aliphatic organic enamel safe acids are selected form thegroup consisting of: acetic acid; acetoacetic acid; acrylic acid; anisicacid; ascorbic acid; formic acid; glutaric acid; glycolic acid; succinicacid; and adipic acid; and mixtures thereof.

Preferred aromatic organic enamel safe acids are selected form the groupconsisting of: benzoic acid; o-aminobenzoic acid; m-aminobenzoic acid;p-aminobenzoic acid; 3,4-dihydroxybenzoic acid; 3,5-dihydroxybenzoicacid; and phenylacetic; and mixtures thereof.

Preferred inorganic enamel safe acids are selected form the groupconsisting of: telluric acid; carbonic acid; and hypochlorous acid; andmixtures thereof.

Even more preferred enamel safe acids having a pK_(a) of 3.5 or higherare selected form the group consisting of: acetic acid; acetoaceticacid; glutaric acid; adipic acid; succinic acid; and benzoic acid; andmixtures thereof. The most preferred enamel safe acids having a pK_(a)of 3.5 or higher are selected form the group consisting of: acetic acid;giutaric acid; adipic acid; and succinic acid; and mixtures thereof.

Suitable acids are commercially available from Aldrich, ICI and BASF.

The present invention is based on the finding that a process of cleaningenamel with a liquid acidic composition comprising an enamel safe acidas described herein is safe to enamel surfaces.

In a preferred embodiment according to the present invention thecompositions used in a process of cleaning an enamel surface do notcomprise any acids having a pK_(a) of less than 3.5, more preferablyless than 4.0.

Another aspect of the present invention is the use of an enamel safeacid in a composition to clean an enamel surface wherein the pK_(a) ofsaid acid is 3.5 or higher; whereby said composition is safe to enamel.

By “safe to enamel surfaces” it is meant herein that the acidiccompositions as described herein prevent or at least reduce damage toenamel surfaces treated therewith as compared to other acidiccompositions.

It is believed that damage to enamel surfaces may be caused by cations,most likely small cations, i.e., cations having an ionic radius of 115pm or less, present in an acidic composition used to treat said enamelsurface. Such cations may be present in acidic compositions for examplewhere a buffer ingredient or a buffering system is used to adjust the pHof said composition. The cations are believed to penetrate and spreadthrough the superficial layers of the crystalline lattice of enamel.Said cations may eventually replace cations originally present in saidsuperficial layers of the crystalline lattice of enamel and/or otherwisemodify said superficial layers of the crystalline lattice of enamel. Theresult of such a replacement is that the enamel surface eventuallylooses its smoothness and consequently its gloss, i.e., shine. The lossof gloss is perceived by consumers as damage to an enamel surface.

Whilst not wishing to be bound by theory, it is believed that by usingan acid having a pK_(a) of 3.5 or higher in an enamel cleaningcomposition, the pH of said composition is in an optimal range toachieve good cleaning performance whilst still being safe to the treatedenamel surface, i.e., the composition is acidic, preferably the pH isbelow 7, more preferably the pH is from 1 to 6.5, still more preferablythe pH is from 1 to 5, even more preferably the pH is from 2 to 5 andmost preferably the pH is from 2 to 4, and therefore, the pH does notneed further adjustment. Thus, there is no need to employ a bufferingredient or a buffering system other than the enamel safe acid itself.Thus, it is believed that less enamel-damaging cations are present inthe enamel cleaning composition.

Thus, the compositions used in a process to clean an enamel surface asdescribed herein are safe to said enamel surfaces.

The degree of enamel damage can be determined by the following enameldamage test method

Enamel Damage Test Method

A few drops of the composition according to the present invention in itsneat or dilute form are placed on an enamel surface (e.g., an enameltile) afterwards, the surface is covered with a watch-glass. After 15minutes, the watch-glass is removed, the enamel surface is rinsed withwater (either demineralised or tap) and then wiped dry. Visualexamination (visual grading) or gloss measurements of the surface allowto verify whether the product is safe (no difference of gloss versus theuntreated enamel surface) or unsafe (difference of gloss versus theuntreated enamel surface) to enamel.

Optional Surfactant

The liquid compositions of the present invention may preferably comprisea surfactant. Surfactants may be desired herein as they furthercontribute to the cleaning performance of the compositions of thepresent invention.

Surfactants to be used herein include nonionic surfactants, cationicsurfactants, anionic surfactants, zwitterionic surfactants, amphotericsurfactants, and mixtures thereof.

Accordingly, the compositions according to the present invention maycomprise up to 15%, more preferably from 0.5% to 8%, even morepreferably from 0.5% to 8%, and most preferably 0.5% to 8% by weight ofthe total composition of a surfactant.

Suitable nonionic surfactants for use herein include a class ofcompounds, which may be broadly defined as compounds produced by thecondensation of alkylene oxide groups (hydrophilic in nature) with anorganic hydrophobic compound, which may be branched or linear aliphatic(e.g., Guerbet or secondary alcohol) or alkyl aromatic in nature. Thelength of the hydrophilic or polyoxyalkylene radical which is condensedwith any particular hydrophobic group can be readily adjusted to yield awater-soluble compound having the desired degree of balance betweenhydrophilic and hydrophobic elements. Accordingly suitable nonionicsynthetic detergents include:

(i) The polyethylene oxide condensates of alkyl phenols, e.g., thecondensation products of alkyl phenols having an alkyl group containingfrom 6 to 20 carbon atoms in either a straight chain or branched chainconfiguration, preferably from 8 to 14, and more preferably from 8 to 12carbon atoms, with ethylene oxide. Said ethylene oxide is typicallypresent in amounts of from 3 to 25, preferably from 10 to 25 moles ofethylene oxide per mole of alkyl phenol. The alkyl substituent in suchcompounds may be derived from polymerized propylene, diisobutylene,octane, and nonane; Examples of this type of nonionic surfactantsinclude Triton N-57® a nonyl phenol ethoxylate (5EO) from Rohm & Haasand Imbentin O200® an octyl phenol ethoxylate (20EO) from KOLB.

(ii) Those derived from the condensation of ethylene oxide with theproduct resulting from the reaction of propylene oxide and ethylenediamine products which may be varied in composition depending upon thebalance between the hydrophobic and hydrophilic elements which isdesired. Examples are compounds containing from 40% to 80%polyoxyethylene by weight and having a molecular weight of from 5000 to11000 resulting from the reaction of ethylene oxide groups with ahydrophobic base constituted of the reaction product of ethylene diamineand excess propylene oxide, said base having a molecular weight of theorder of 2500 to 3000. Examples of this type of nonionic surfactantsinclude certain of the commercially available Tetronic™ compounds,marketed by BASF.

(iii) The condensation product of aliphatic alcohols having from 2 to 24carbon atoms, in either straight chain or branched chain configuration,preferably from 6 to 22, more preferably from 6 to 28, and even morepreferably 8 to 18 carbon atoms, with from 2 to 35, preferably from 4 to25, more preferably from 5 to 18, and even more preferably 3 to 15 molesof ethylene oxide. Examples of this type of material are a coconutalcohol ethylene oxide condensate having from 5 to 18 moles of ethyleneoxide per mole of coconut alcohol, the coconut alcohol fraction havingfrom 9 to 14 carbon atoms. Other examples of this type of nonionicsurfactants include certain of the commercially available Dobanol®,Neodol® marketed by Shell or Lutensol® from BASF. For example Dobanol®23.5 (C12-C13 EO5), Dobanol® 91.5 (C9-C11 EO5), Dobanol® 91.8 (C9-C11EO8) and Lutensol® AO30 (C12-C14 EO30).

(iv) Trialkyl amine oxides and trialkyl phosphnine oxides wherein onealkyl group ranges from 10 to 18 carbon atoms and two alkyl groupsranges from 1 to 3 carbon atoms; the alkyl groups can contain hydroxysub stituents; specific examples are dodecyl di(2-hydroxyethyl)amineoxide and tetradecyl dimethyl phosphine oxide,

(v) The condensation products of ethylene oxide with a hydrophobic baseformed by the condensation of propylene oxide with propylene glycol; Thehydrophobic portion of these compounds will preferably have a molecularweight of from 1500 to 1800 and will exhibit water insolubility. Theaddition of polyoxyethylene moieties to this hydrophobic portion tendsto increase the water solubility of the molecule as a whole, and theliquid character of the product is retained up to the point where thepolyoxyethylene content is 50% of the total weight of the condensationproduct, which corresponds to condensation with up to 40 moles ofethylene oxide. Examples of compounds of this type include certain ofthe commercially available Pluronic™ surfactants, marketed by BASF.

Also useful as a nonionic surfactant are the alkylpolysaccharidesdisclosed in U.S. Pat. No. 4,565,647, Lienado, issued Jan. 21, 1986,having a hydrophobic group containing from 6 to 30 carbon atoms,preferably from 10 to 16 carbon atoms and polysaccharide, e.g., apolyglycoside, hydrophilic group containing from 1.3 to 10, preferablyfrom 1.3 to 3, most preferably from 1.3 to 2.7 saccharide units. Anyreducing saccharide containing 5 or 6 carbon atoms can be used, e.g.,glucose, galactose, and galactosyi moieties can be substituted for theglucosyl moieties. (Optionally the hydrophobic group is attached at the2-, 3-, 4-, etc. positions thus giving a glucose or galactose as opposedto a glucoside or galactoside.) The intersaccharide bonds can be, e.g.,between the one position of the additional saccharide units and the 2-,3-, 4-, and/or 6-positions of the preceding saccharide units.

Optionally, and less desirable, there can be a polyalkyleneoxide chainjoining the hydrophobic moiety and the polysaccharide moiety. Thepreferred alkyleneoxide is ethylene oxide. Typical hydrophobic groupsinclude alkyl groups, either saturated or unsaturated, branched orunbranched containing from 8 to 18, preferably from 10 to 16, carbonatoms. Preferably, the alkyl group can contain up to 3 hydroxy groupsand/or the polyalkyleneoxide chain can contain up to 10, preferably lessthan 5, alkyleneoxide moieties. Suitable alkyl polysaccharides areoctyl, nonyidecyl, undecyldodecyl, tridecyl, tetradecyl, pentadecyl,hexadecyl, heptadecyl, and octadecyl, di-, tri-, tetra-, penta-, andhexaglucosides, galactosides, lactosides, glucoses, fructosides,fructoses and/or galactoses. Suitable mixtures include coconut alkyl,di-, tri-, tetra-, and pentaglucosides and tallow alkyl tetra-, penta-,and hexaglucosides.

The preferred alkylpolyglycosides have the formula:

R²O(C_(n)H_(2n)O)_(t)(glucosyl)_(x)

wherein R² is selected from the group consisting of alkyl, alkylphenyl,hydroxyalkyl, hydroxyalkylphenyl, and mixtures thereof in which thealkyl groups contain from 10 to 18, preferably from 12 to 14, carbonatoms; n is 2 or 3, preferably 2; t is from 0 to 10, preferably 0; and xis from 1.3 to 10, preferably from 1.3 to 3, most preferably from 1.3 to2.7. The glycosyl is preferably derived from glucose. To prepare thesecompounds, the alcohol or alkylpolyethoxy alcohol is formed first andthen reacted with glucose, or a source of glucose, to form the glucoside(attachment at the 1-position). The additional glycosyl units can thenbe attached between their 1-position and the preceding glycosyl units2-, 3-, 4- and/or 6-position, preferably predominantely. the 2-position.

Other suitable nonionic surfactants for use herein include polyhydroxyfatty acid amides of the structural formula:

 R²—C—N—Z  (I)

wherein: R¹ is H, C₁-C₄ hydrocarbyl, 2-hydroxy ethyl, 2-hydroxypropyl,or a mixture thereof, preferably C₁-C₄ alkyl, more preferably C₁ or C₂alkyl, most preferably C₁ alkyl (i.e., methyl); and R² is a C₅-C₃₁hydrocarbyl, preferably straight chain C₇-C₁₉ alkyl or alkenyl, morepreferably straight chain C₉-C₁₇ alkyl or alkenyl, most preferablystraight chain C₁₁-C₁₇ alkyl or alkenyl, or mixtures thereof; and Z is apolyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3hydroxyls directly connected to the chain, or an alkoxylated derivative(preferably ethoxylated or propoxylated) thereof Z preferably will bederived from a reducing sugar in a reductive amination reaction; morepreferably Z is a glycityl. Suitable reducing sugars include glucose,fructose, maltose, lactose, galactose, mannose, and xylose. As rawmaterials, high dextrose corn syrup can be utilized as well as theindividual sugars listed above. These corn syrups may yield a mix ofsugar components for Z. It should be understood that it is by no meansintended to exclude other suitable raw materials. Z preferably will beselected from the group consisting of —CH₂—(CHOH)_(n)—CH₂OH,—CH(CH₂OH)—(CHOH)_(n−1)—CH₂OH, —CH₂—(CHOH)₂(CHOR′)(CHOH)—CH₂OH, where nis an integer from 3 to 5, inclusive, and R′ is H or a cyclic oraliphatic monosaccharide, and alkoxylated derivatives thereof. Mostpreferred are glycityls wherein n is 4, particularly —CH₂—(CHOH)₄—CH₂OH.

In Formula (I), R¹ can be, for example, N-methyl, N-ethyl, N-propyl,N-isopropyl, N-butyl, N-2-hydroxy ethyl, or N-2-hydroxy propyl. R²—CO—N<can be, for example, cocamide, stearamide, oleamide, lauramide,myristamide, capricamide, palmitamide, tallowamide, etc. Z can be1-deoxyglucityl, 2-deoxyfructityl, 1-deoxymaltityl, 1-deoxylactityl,1-deoxygalactityl, 1-deoxymannityl, 1-deoxymaltotriotityl, etc.

Other suitable nonionic surfactants for use herein include the amineoxides corresponding to the formula:

RR′R″N→O

wherein R is a primary alkyl group containing from 6 to 24 carbons,preferably from 10 to 18 carbons, and wherein R″ and R″ are, each,independently, an alkyl group containing 1 to 6 carbon atoms. The arrowin the formula is a conventional representation of a semi-polar bond.The preferred amine oxides are those in which the primary alkyl grouphas a straight chain in at least most of the molecules, generally atleast 70%, preferably at least 90% of the molecules, and the amineoxides which are especially preferred are those in which R contains from10 to 18 carbons and R′ and R″ are both methyl. Exemplary of thepreferred amine oxides are the N-hexyldimethylamine oxide,N-octyidimethylamine oxide, N-decyldimethylamine oxide, N-dodecyldimethylamine oxide, N-tetradecyidimethylamine oxide, N-hexadecyldimethylamine oxide, N-octadecyldimethylamine oxide,N-eicosyldimethylamine oxide, N-docosyldimethylamine oxide, N-tetracosyldimethylamine oxide, the corresponding amine oxides in which one or bothof the methyl groups are replaced with ethyl or 2-hydroxyethyl groupsand mixtures thereof. A most preferred amine oxide for use herein isN-decyidimethylamine oxide.

Other suitable nonionic surfactants for the purpose of the invention arethe phosphine or sulfoxide surfactants of formula:

RR′R″A→O

wherein A is phosphorus or sulfur atom, R is a primary alkyl. groupcontaining 6-24 carbons, preferably 10-18 carbons, and wherein R′ and R″are, each, independently selected from methyl, ethyl and 2-hydroxyethyl.The arrow in the formula is a conventional representation of asemi-polar bond.

In a preferred embodiment herein suitable nonionic surfactants to beused are polyethylene oxide condensates of alkyl phenols, polyethyleneoxide condensates of alkyl alcohols, alkylpolysaccharides, or mixturesthereof. Highly preferred are C₆-C₂₀, preferably C₈-C₁₂ alkyl phenolethoxylates having from 3 to 25, preferably 10 to 25 ethoxy groups andC₂-C₂₄, preferably C₈-C₁₈ alcohol ethoxylates having from 2 to 35,preferably from 4 to 25, more preferably from 5 to 18 and mostpreferably from 3 to 15 ethylene oxide units, and mixtures thereof.

Suitable zwitterionic surfactants for use herein contain both basic andacidic groups which form an inner salt giving both cationic and anionichydrophilic groups on the same molecule at a relatively wide range ofpH's. The typical cationic group is a quaternary ammonium group,although other positively charged groups like phosphonium, imidazoliumand sulfonium groups can be used. The typical anionic hydrophilic.groups are carboxylates and sulfonates, although other groups likesulfates, phosphonates, and the like can be used.

A generic formula for preferred zwitterionic surfactants for use herein(i.e., betaine and/or sulfobetaine) is:

R₁—N⁺(R₂)(R₃)R₄X⁻

wherein R₁ is a hydrophobic group; R₂ is hydrogen, C₁-C₆ alkyl, hydroxyalkyl or other substituted C₁-C₆ alkyl group; R₃ is C₁-C₆ alkyl, hydroxyalkyl or other substituted C₁-C₆ alkyl group which can also be joined toR₂ to form ring structures with the N, or a C₁-C₆ carboxylic acid groupor a C₁-C₆ sulfonate group; R₄ is a moiety joining the cationic nitrogenatom to the hydrophilic group and is typically an alkylene, hydroxyalkylene, or polyalkoxy group containing from 1to 10 carbon atoms; and Xis the hydrophilic group which is a carboxylate or sulfonate group,preferably sulfonate group.

Preferred hydrophobic groups R₁ are aliphatic or aromatic, saturated orunsaturated, substituted or unsubstituted hydrocarbon chains that cancontain linking groups such as amido groups, ester groups. Morepreferred R₁ is an alkyl group containing from 1 to 24, preferably from8 to 18, and more preferably from 10 to 16 carbon atoms. These simplealkyl groups are preferred for cost and stability reasons. However, thehydrophobic group R₁ can also be an amido radical of the formulaR_(a)—C(O)—NR_(b)—(C(R_(c))₂)_(m), wherein R_(a) is an aliphatic oraromatic, saturated or unsaturated, substituted or unsubstitutedhydrocarbon chain containing from 8 up to 20 carbon atoms, preferably analkyl group containing from 8 up to 20, preferably up to 18, morepreferably up to 16 carbon atoms, R_(b) is either a hydrogen a shortchain alkyl or substituted alkyl containing from 1 to 4 carbon atoms,preferably a group selected from the group consisting of methyl, ethyl,propyl, hydroxy substituted ethyl or propyl and mixtures thereof, morepreferably methyl or hydrogen, R_(c) is selected from the groupconsisting of hydrogen and hydroxy groups, and m is from 1 to 4,preferably from 2 to 3, more preferably 3, with no more than one hydroxygroup in any (C(R_(c))₂) moiety.

Preferred R₂ is hydrogen, or an alkyl or substituted alkyl containingfrom 1 to 4 carbon atoms, preferably a group selected from the groupconsisting of methyl, ethyl, propyl, hydroxy substituted ethyl or propyland mixtures thereof, more preferably methyl. Preferred R₃ is a C₁-C₄carboxylic acid group, a C₁-C₄ sulfonate group, or, an alkyl orsubstituted alkyl containing from 1 to 4 carbon atoms, preferably agroup selected from the group consisting of methyl, ethyl, propyl,hydroxy substituted ethyl or propyl and mixtures thereof, morepreferably methyl. Preferred R₄ is (CH₂)_(n) wherein n is an integerfrom 1 to 10, preferably from 1 to 6, more preferably is from 1 to 3.

Some common examples of betaine/sulphobetaine are described in U.S. Pat.Nos. 2,082,275, 2,702,279 and 2,255,082, incorporated herein byreference.

Examples of particularly suitable alkyidimethyl betaines includecoconut-dimethyl betaine, lauryl dimethyl betaihe, decyl dimethylbetaine, 2-(N-decyl-N, N-dimethyl-ammonia)acetate, 2-(N-coco N,N-dimethylammonio) acetate, myristyl dimethyl betaine, palmityl dimethylbetaine, cetyl dimethyl betaine, stearyl dimethyl betaine. For exampleCoconut dimethyl betaine is commercially available from Seppic under thetrade name of Amonyl 265®. Lauryl betaine is commercially available fromAlbright & Wilson under the trade name Empigen BB/L®.

A further example of betaine is Lauryl-immino-dipropionate commerciallyavailable from Rhone-Poulenc under the trade name Mirataine H2C-HA®.

Particularly preferred zwitterionic surfactants for use in thecompositions of the present invention are the sulfobetaine surfactantsas they deliver optimum grease cleaning benefits.

Examples of particularly suitable sulfobetaine surfactants includetallow bis(hydroxyethyl) sulphobetaine, cocoamido propyl hydroxysulfobetaines which are commercially available from Rhone Poulenc andWitco, under the trade name of Mirataine CBSX and Rewoteric AM CAS 15®respectively.

Further examples of amidobetaines/amidosulfobetaine includecocoamidoethylbetaine, cocoamidopropyl betaine or C₁₀-C₁₄ fattyacylamidopropylene(hydropropylene)sulfobetaine. For example C₁₀-C₁₄fatty acylamidopropylene(hydropropylene)sulfobetaine is commerciallyavailable from Sherex Company under the trade name “Varion CAS®sulfobetaine”.

Suitable amines for use herein are according to the following formulaRR′R″N wherein R is a saturated or unsaturated, substituted orunsubstituted, linear or branched alkyl groups containing from 1 to 30carbon atoms, and preferably from 1 to 20 carbon atoms and wherein R′and R″ are independently saturated or unsaturated, substituted orunsubstituted,. linear or branched alkyl groups containing from 1 to 30carbon atoms or hydrogen. Particularly preferred amines to be usedaccording to the present invention are amines having the followingformula RR′R″N wherein R is a saturated or unsaturated, linear orbranched alkyl group containing from 1 to 30 carbon atoms, preferablyfrom 8 to 20, more preferably from 6 to 16, most preferably from 8 to 14carbon atoms and wherein R′ and R″ are independently substituted orunsubstituted, linear or branched alkyl groups containing from 1 to 4carbon atoms, preferably from 1 to 3 carbon atoms, and more preferablyare methyl groups, or mixtures thereof.

Suitable amines for use herein are for instance C₁₂ dimethyl amine,coconut dimethyl amine, C₁₂-C₁₆ dimethyl amine. Said amines may becommercially available from Hoechst under the trade name Genamin®, AKZOunder the trade name Aromox® or Fina under the trade name Radiamine®.

Suitable quatemary ammonium surfactants for use herein are according tothe formula R₁R₂R₃R₄N⁺X⁻, wherein X is a counteranion such as halogen,methyl sulphate, methyl sulphonate, or hydroxide, R₁ is a saturated orunsaturated, substituted or unsubstituted, linear or branched alkylgroup containing from 1 to 30 carbon atoms, preferably from 12 to 20,more preferably from 8 to 20 carbon atoms and R₂, R₃ and R₄ areindependently hydrogen, or saturated or unsaturated, substituted orunsubstituted, linear or branched alkyl groups containing from 1 to 4carbon atoms, preferably from 1 to 3 and more preferably methyl. Inhighly preferred quatemary ammonium surfactants herein R₁ is a C₁₀-C₁₈hydrocarbon chain, most preferably C₁₂, C₁₄, or C₁₆, and R₂, R₃ and R₄are all three methyl, and X is halogen, preferably bromide or chloride,most preferably bromide.

Examples of quaternary ammonium surfactants are myristyltrimethylammonium methyl sulphate, cetyl trimethylammonium methylsulphate, lauryl trimethyl ammonium bromide, stearyl trimethyl ammoniumbromide (STAB), cetyl trimethyl ammonium bromide (CTAB) and myristyltrimethyl ammonium bromide (MTAB). Highly preferred herein are lauryltrimethyl ammonium salts. Such trimethyl quaternary ammonium surfactantsmay be commercially available from Hoechst, or from Albright & Wilsonunder the trade name Empigen CM®.

Cationic surfactants suitable for use in compositions of the presentinvention are those having a long-chain hydrocarbyl group. Examples ofsuch cationic surfactants include the ammonium surfactants such asalkyldimethylammonium halogenides, and those surfactants having theformula:

[R²(OR³)_(y)][R⁴(OR³)_(y)]₂R⁵N⁺X⁻

wherein R² is an alkyl or alkyl benzyl group having from 8 to 18 carbonatoms in the alkyl chain, each R³ is selected from the group consistingof —CH₂CH₂—, —CH₂CH(CH₃)—, —CH₂CH(CH₂OH)—, —CH₂CH₂CH₂—, and mixturesthereof; each R⁴ is selected from the group consisting of C₁-C₄ alkyl,C₁-C₄ hydroxyalkyl, benzyl ring structures formed by joining the two R⁴groups, —CH₂CHOH—CHOHCOR⁶CHOHCH₂OH wherein R⁶ is any hexose or hexosepolymer having a molecular weight less than 1000, and hydrogen when y isnot 0; R⁵ is the same as R⁴ or is an alkyl chain wherein the totalnumber of carbon atoms of R² plus R⁵ is not more than 18; each y is from0 to 10 and the sum of the y values is from 0 to 15; and X is anycompatible anion.

Other cationic surfactants useful herein are also described in U.S. Pat.No. 4,228,044, Cambre, issued Oct. 14, 1980, incorporated herein byreference.

Amphoteric and ampholytic detergents which can be either cationic oranionic depending upon the pH of the system are represented bydetergents such as dodecylbeta-alanine, N-alkyltaurines such as the oneprepared by reacting dodecylamine with sodium isethionate according tothe teaching of U.S. Pat. No. 2,658,072, N-higher alkylaspartic acidssuch as those produced according to the teaching of U.S. Pat. No.2,438,091, and the products sold under the trade name “Miranol”, anddescribed in U.S. Pat. No. 2,528,378, said patents being incorporatedherein by reference. Additional synthetic detergents and listings oftheir commercial sources can be found in McCutcheon's Detergents andEmulsifiers, North American Ed. 1980, incorporated herein by reference.

Suitable anionic surfactants for use herein are all those commonly knownby those skilled in the art. Preferably, the anionic surfactants for useherein include alkyl sulphonates, alkyl aryl sulphonates, alkylsulphates, alkyl alkoxylated sulphates, C₆-C₂₀ alkyl alkoxylated linearor branched diphenyl oxide disulphonates, or mixtures thereof.

Suitable alkyl sulphonates for use herein include water-soluble salts oracids of the formula RSO₃M wherein R is a C₆-C₂₀ linear or branched,saturated or unsaturated alkyl group, preferably a C₈-C₁₈ alkyl groupand more preferably a C₁₀-C₁₆ alkyl group, and M is H or a cation, e.g.,an alkali metal cation (e.g., sodium, potassium, lithium), or ammoniumor substituted ammonium (e.g., methyl-, dimethyl-, and trimethylammonium cations and quaternary ammonium cations, such astetramethyl-ammonium and dimethyl piperdinium cations and quaternaryammonium catioris derived from alkylamines such as ethylamine,diethylamine, triethylamine, and mixtures thereof, and the like).

Suitable alkyl aryl sulphonates for use herein include water-solublesalts or acids of the formula RSO₃M wherein R is an aryl, preferably abenzyl, substituted by a C₆-C₂₀ linear or branched saturated orunsaturated alkyl group, preferably a C₈-C₁₈ alkyl group and morepreferably a C₁₀-C₁₆ alkyl group, and M is H or a cation, e.g., analkali metal cation (e.g., sodium, potassium, lithium, calcium,magnesium and the like) or ammonium or substituted ammonium (e.g.,methyl-, dimethyl-, and trirnethyl ammonium cations and quatemaryammonium cations, such as tetramethyl-ammonium and dimethyl piperdiniumcations and quaternary ammonium cations derived from alkylamines such asethylamine, diethylamine, triethylamine, and mixtures thereof, and thelike).

An example of a C₁₄-C₁₆ alkyl sulphonate is Hostapure SAS available fromHoechst. An example of commercially available alkyl aryl sulphonate isLauryl aryl sulphonate from Su.Ma. Particularly preferred alkyl arylsulphonates are alkyl benzene sulphonates commercially available undertrade name Nansa® available from Albright&Wilson.

Suitable alkyl sulphate surfactants for use herein are according to theformula R₁SO₄M wherein R₁ represents a hydrocarbon group selected fromthe group consisting of straight or branched alkyl radicals containingfrom 6 to 20 carbon atoms and alkyl phenyl radicals containing from 6 to18 carbon atoms in the alkyl group. M is H or a cation, e.g., an alkalimetal cation (e.g., sodium, potassium, lithium, calcium, magnesium andthe like) or ammonium or substituted ammonium (e.g., methyl-, dimethyl-,and trimethyl ammonium cations and quatemary ammonium cations, such astetramethyl-ammonium and dimethyl piperdinium cations and quaternaryammonium cations derived from alkylamines such as ethylamine,diethylamine, triethylamine, and mixtures thereof, and the like).

Particularly preferred branched alkyl sulphates to be used herein arethose containing from 10 to 14 total carbon atoms like Isalchem 123 AS®.Isalchem 123 AS® commercially available from Enichem is a C₁₂₋₁₃surfactant which is 94% branched. This material can be described asCH₃—(CH₂)_(m)—CH(CH₂OSO₃Na)—(CH₂)_(n)—CH₃ where n+m=8-9. Also preferredalkyl sulphates are the alkyl sulphates where the alkyl chain comprisesa total of 12 carbon atoms, i.e., sodium 2-butyl octyl sulphate. Suchalkyl sulphate is commercially available from Condea under the tradename Isofol® 12S. Particularly suitable liner alkyl sulphonates includeC₁₂-C₁₆ paraffin sulphonate like Hostapur® SAS commercially availablefrom Hoechst.

Suitable alkyl alkoxylated sulphate surfactants for use herein areaccording to the formula RO(A)_(m)SO₃M wherein R is an unsubstitutedC₆-C₂₀ alkyl or hydroxyalkyl group having a C₆-C₂₀ alkyl component,preferably a C₁₂-C₂₀ aalkyl or hydroxyalkyl, more preferably C₁₂-C₁₈alkyl or hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater thanzero, typically between 0.5 and 6, more preferably between 0.5 and 3,and M is H or a cation which can be, for example, a metal cation (e.g.,sodium, potassium, lithium, calcium, magnesium, etc.), ammonium orsubstituted-ammonium cation. Alkyl ethoxylated sulfates as well as alkylpropoxylated sulfates are contemplated herein. Specific examples ofsubstituted ammonium cations include methyl-, dimethyl-,trimethyl-ammonium and quaternary ammonium cations, such astetramethyl-ammonium, dimethyl piperdinium and cations derived fromalkanolamines such as ethylamine, diethylamine, triethylamine, mixturesthereof, and the like. Exemplary surfactants are C₁₂-C₁₈ alkylpolyethoxylate (1.0) sulfate (C₁₂-C₁₈E(1.0)SM), C₁₂-C₁₈ alkylpolyethoxylate (2.25) sulfate. (C₁₂-C₁₈E(2.25)SM), C₁₂-C₁₈ alkylpolyethoxylate (3.0) sulfate (C₁₂-C₁₈E(3.0)SM), and C₁₂-C₁₈ alkylpolyethoxylate (4.0) sulfate (C₁₂-C₁₈E(4.0)SM), wherein M isconveniently selected from sodium and potassium.

Suitable C₆-C₂₀ alkyl alkoxylated linear or branched diphenyl oxidedisulphonate surfactants for use herein are according to the followingformula:

wherein R is a C₆-C₂₀ linear or branched, saturated or unsaturated alkylgroup, preferably a C₁₂-C₁₈ alkyl group and more preferably a C₁₄-C₁₆alkyl group, and X+ is H or a cation, e.g., an alkali metal cation(e.g., sodium, potassium, lithium, calcium, magnesium and the like).Particularly suitable C₆-C₂₀ alkyl alkoxylated linear or brancheddiphenyl oxide-disulphonate surfactants to be used herein are the C12branched di phenyl oxide disulphonic acid and C16 linear di phenyl oxidedisulphonate sodium salt respectively commercially available by DOWunder the trade name Dowfax 2A1® and Dowfax 8390®.

Other anionic surfactants useful herein include salts (including, forexample, sodium, potassium, ammonium, and substituted ammonium saltssuch as mono-, di- and triethanolamine salts) of soap, C₈-C₂₄olefinsulfonates, sulphonated polycarboxylic acids prepared bysulphonation of the pyrolyzed product of alkaline earth metal citrates,e.g., as described in British patent specification No. 1,082,179, C₈-C₂₄alkylpolyglycolethersulfates (containing up to 10 moles of ethyleneoxide); alkyl ester sulfonates such as C₁₄₋₁₆ methyl ester sulfonates;acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyl phenolethylene oxide ether sulfates, alkyl phosphates, isethionates such asthe acyl isethionates, N-acyl taurates, alkyl succinamates andsulfosuccinates, monoesters of sulfosuccinate (especially saturated andunsaturated C₁₂-C₁₈ monoesters) diesters of sulfosuccinate (especiallysaturated and unsaturated C₆-C₁₄ diesters), acyl sarcosinates, sulfatesof alkylpolysaccharides such as the sulfates of alkylpolyglucoside (thenonionic nonsulfated compounds being described below), alkyl polyethoxycarboxylates such as those of the formula RO(CH₂CH₂O)_(k)CH₂COO—M⁺wherein R is a C₈-C₂₂ alkyl, k is an integer from 0 to 10, and M is asoluble salt-forming cation. Resin acids and hydrogenated resin acidsare also suitable, such as rosin, hydrogenated rosin, and resin acidsand hydrogenated resin acids present in or derived from tall oil.Further examples are given in “Surface Active Agents and Detergents”(Vol. I and II by Schwartz, Perry and Berch). A variety of suchsurfactants are also generally disclosed in U.S. Pat. No. 3,929,678,issued Dec. 30, 1975 to Laughlin, et al. at Column 23, line 58 throughColumn 29, line 23.

Preferably the surfactants to be used herein as optional ingredients areselected from the group consisting of nonionic. surfactants, cationicsurfactants, anionic surfactants, zwitterionic surfactants, amphotericsurfactants, and mixtures thereof. More preferably said surfactant is anonionic surfactant or an anionic surfactant or a mixture thereof.

Other Optional Ingredients

The compositions herein may further comprise conventional enamelcleaning ingredients. Preferably, the liquid compositions according tothe present invention may comprise a variety of optional ingredientsdepending on the technical benefit aimed for and the surface treated.

Suitable optional ingredients for use herein include a solvent, abuilder, a chelant, a bactericide, a hydrotrope, a colorant, astabilizer, a radical, scavenger, a vinylpyrrolidone homopolymer orcopolymer, a polysaccharide polymer, a bleach, a bleach activator, apreservative, a suds controlling agent like a fatty acid, an enzyme, asoil suspender, a dye transfer agent, a brightener, an anti dustingagent, a dispersant, a dye transfer inhibitor, a pigment, a dye and/or aperfume.

Solvent

The compositions of the present invention may further comprise asolvent, as a highly preferred optional ingredient.

Solvents are desired herein because they contribute to the greasy soilscleaning performance of the composition herein.

Suitable solvents for use herein include glycols or alkoxylated glycols,alkoxylated aromatic alcohols, aromatic alcohols, aliphatic branchedalcohols, alkoxylated aliphatic branched alcohols, alkoxylated linearC₁-C₅ alcohols, linear C₁-C₅ alcohols, C₈-C₁₄ alkyl and cycloalkylhydrocarbons and halohydrocarbons and mixtures thereof with the provisothat said solvent is not a mono-lower alkyl ether or phenyl ether orbenzyl ether of diethylene glycol, wherein the lower alkyl is of 2 to 6carbon atoms.

Suitable glycols to be used herein are according to the formulaHO—CR₁R₂—OH wherein R₁ and R₂ are independently H or a C₂-C₁₀ saturatedor unsaturated aliphatic hydrocarbon chain and/or cyclic. Suitableglycols to be used herein are dodecaneglycol and/or propanediol.

Suitable alkoxylated glycols to be used herein are according to theformula R—(A)_(n)—R₁—OH wherein R is H, OH, a linear saturated orunsaturated alkyl of from 1 to 20 carbon atoms, preferably from 2 to 15and more preferably from 2 to 10 carbon atoms, wherein R₁ is a linearsaturated or unsaturated alkyl of from 3 to 20 carbon atoms, preferablyfrom 3 to 15 and more preferably from 3 to 10 carbon atoms, and A is analkoxy group preferably ethoxy, methoxy, and/or propoxy and n is from 1to 5, preferably 1 to 2. Suitable alkoxylated glycols to be used hereinare methoxy octadecanol and/or ethoxyethoxyethanol.

Suitable alkoxylated aromatic alcohols to be used herein are accordingto the formula R—(A)_(n)—OH wherein R is an alkyl substituted ornon-alkyl substituted aryl group of from 1 to 20 carbon atoms,preferably from 2 to 15 and more preferably from 2 to 10 carbon atoms,wherein A is an alkoxy group preferably butoxy, propoxy and/or ethoxy,and n is an integer of from 1 to 5, preferably 1 to 2, with the provisothat n is not an integer of 2 if A is an ethoxy group. Suitablealkoxylated aromatic alcohols are benzoxyethanol and/or benzoxypropanol.

Suitable aromatic alcohols to be used herein are according to theformula R—OH wherein R is an alkyl substituted or non-alkyl substitutedaryl group of from 1 to 20 carbon atoms, preferably from 1 to 15 andmore preferably from 1 to 10 carbon atoms. For example a suitablearomatic alcohol to be used herein is benzyl alcohol.

Suitable aliphatic branched alcohols to be used herein are according tothe formula R—OH wherein R is a branched saturated or unsaturated alkylgroup of from 1 to 20 carbon atoms, preferably from 2 to 15 and morepreferably from 5 to 12 carbon atoms. Particularly, suitable aliphaticbranched alcohols to be used herein include 2-ethylbutanol and/or2-methylbutanol.

Suitable alkoxylated aliphatic branched alcohols to be used herein areaccording to the formula R—(A)_(n)—OH wherein R is a branched saturatedor unsaturated alkyl group of from 1 to 20 carbon atoms, preferably from2 to 15 and more preferably from 5 to 12 carbon atoms, wherein A is analkoxy group preferably butoxy, propoxy and/or ethoxy, and n is aninteger of from 1 to 5, preferably 1 to 2, with the proviso that n isnot an integer of 2, if A is an ethoxy group. Suitable alkoxylatedaliphatic branched alcohols include 1-methylpropoxyethanol and/or2-methylbutoxyethanol.

Suitable alkoxylated linear C₁C₅ alcohols to be used herein areaccording to the formula R—(A)_(n)—OH wherein R is a linear saturated orunsaturated alkyl group of from 1 to 5 carbon atoms, preferably from 2to 4 carbon atoms, wherein A is an alkoxy group preferably butoxy,propoxy and/or ethoxy, and n is an integer of from 1 to 5, preferably 1to 2, with the proviso that n is not an integer of 2 if A is an ethoxygroup. Suitable alkoxylated aliphatic linear C₁-C₅ alcohols are butoxypropoxy propanol (n-BPP), butoxyethanol, butoxypropanol, ethoxyethanolor mixtures thereof. Butoxy propoxy propanol is commercially availableunder the trade name n-BPP® from Dow chemical.

Suitable linear C₁-C₅ alcohols to be used herein are according to theformula R—OH wherein R is a linear saturated or unsaturated alkyl groupof from 1 to 5 carbon atoms, preferably from 2 to 4 carbon atoms.Suitable linear C₁-C₅ alcohols are methanol, ethanol, propanol ormixtures thereof.

Other suitable solvents include butyltriglycol ether, ter amilic alcoholand the like. Particularly preferred solvents to be used herein arebutoxy propoxy propanol, benzyl alcohol, butoxypropanol, ethanol,methanol, isopropanol and mixtures thereof.

The preferred solvent for use herein is butoxy propoxy propanol (n-BPP).

Typically, the compositions of the present invention may comprise from0.1% to 8%, preferably from 0.5% to 5% and more preferably from 1% to 3%by weight of the total composition of a solvent.

Vinylpyrrolidone Homopolymer or Copolymer

The compositions of the present invention may comprise avinylpyrrolidone homopolymer or copolymer.

Typically, the compositions of the present invention may comprise from0.01% to 5%, more preferably from 0.05% to 3% and most preferably from0.05% to 1% by weight of the total composition of a vinylpyrrolidonehomopolymer or copolymer.

Suitable vinylpyrrolidone homopolymers for use herein are homopolymersof N-vinylpyrrolidone having the following repeating monomer:

wherein n (degree of polymerisation) is an integer of from 10 to1,000,000, preferably from 20 to 100,000, and more preferably from 20 to10,000.

Accordingly, suitable vinylpyrrolidone homopblymers (“PVP”) for useherein have an average molecular weight of from 1,000 to 100,000,000,preferably from 2,000 to 10,000,000, more preferably from 5,000 to1,000,000, and most preferably from 50,000 to 500,000.

Suitable vinylpyrrolidone homopolymers are commercially available fromISP Corporation, New York, N.Y. and Montreal, Canada under the productnames PVP K-15® (viscosity molecular weight of 10,000), PVP K-30®(average molecular weight of 40,000), PVP K-60® (average molecularweight of 160,000), and PVP K-90® (average molecular weight of 360,000).Other suitable vinylpyrrolidone homopolymers which are commerciallyavailable from BASF Cooperation include Sokalan HP 165® Sokalan HP 12®,Luviskol K30®, Luviskol K60®, Luviskol K80®, Luviskol K90® and othervinylpyrrolidone homopolymers known to persons skilled in the detergentfield (see for example EP-A-262,897 and EP-A-256,696).

Suitable copolymers of vinylpyrrolidone for use herein includecopolymers of N-vinylpyrrolidone and alkylenically unsaturated monomersor mixtures thereof.

The alkylenically unsaturated monomers of the copolymers herein includeunsaturated dicarboxylic acids such as maleic acid, chloromaleic acid,fumaric acid, itaconic acid, citraconic acid, phenylmaleic acid,aconitic acid, acrylic acid, N-vinylimidazole and vinyl acetate. Any ofthe anhydrides of the unsaturated acids may be employed, for exampleacrylate, methacrylate. Aromatic monomers like styrene, sulphonatedstyrene, alpha-methyl styrene, vinyl toluene, t-butyl styrene andsimilar well-known monomers may be used.

The molecular weight of the copolymer of vinylpyrrolidone is notespecially critical so long as the copolymer is water-soluble, has somesurface activity and is adsorbed to the hard-surface from the liquidcomposition comprising it in such a manner as to increase thehydrophilicity of the surface. However, the preferred copolymers ofN-vinylpyrrolidone and alkylenically unsaturated monomers or mixturesthereof, have a molecular weight of between 1,000 and 1,000,000,preferably between 10,000 and 500,000 and more preferably between 10,000and 200,000.

For example particularly suitable N-vinylimidazole N-vinylpyrrolidonepolymers for use herein have an average molecular weight range from5,000 to 1,000,000, preferably from 5,000 to 500,000, and morepreferably from 10,000 to 200,000. The average molecular weight rangewas determined by light scattering as described in Barth H. G. and MaysJ. W. Chemical Analysis Vol 113, “Modern Methods of PolymerCharacterization”.

Such copolymers of N-vinylpyrrolidone and alkylenically unsaturatedmonomers like PVP/vinyl acetate copolymers are commercially availableunder the trade name Luviskol®'series from BASF.

The copolymers of vinylpyrrolidone for use in the compositions of thepresent invention also include quaternized or unquaternizedvinylpyrrolidone/dialkylaminoalkyl acrylate or methacrylate copolymers.

Such vinylpyrrolidone/dialkylaminoalkyl acrylate or methacrylatecopolymers (quaternised or unquatemised) suitable to be used in thecompositions of the present invention are according to the followingformula:

in which n is between 20 and 99 and preferably between 40 and 90 mol %and m is between 1 and 80 and preferably between 5 and 40 mol %; R₁represents H or CH₃; y denotes 0 or 1; R₂ is —CH₂—CHOH—CH₂— orC_(x)H_(2x), in which x=2 to 18; R₃ represents a lower alkyl group. offrom 1 to 4 carbon atoms, preferably methyl or ethyl, or

R₄ denotes a lower alkyl group of from 1 to 4 carbon atoms, preferablymethyl or ethyl; X⁻ is chosen from the group consisting of Cl, Br, I,1/2 SO₄, HSO₄ and CH₃SO₃. The polymers can be prepared by the processdescribed in French Pat. Nos. 2,077,143 and 2,393,573.

The preferred quaternized or unquaternizedvinylpyrrolidone/dialkylaminoalkyl acrylate or methacrylate copolymersfor use herein have a molecular weight of between 1,000 and 1,000,000,preferably between 10,000 and 500,000 and more preferably between 10,000and 100,000.

Such vinylpyrrolidone/dialkylaminoalkyl acrylate or methacrylatecopolymers are commercially available under the name copolymer 845®,Gafquat 734®, or Gafquat 755® from ISP Corporation, New York, N.Y. andMontreal, Canada or from BASF under the tradename Luviquat®.

Preferred vinylpyrrolidone homopolymers or copolymers for use herein arethe vinylpyrrolidone homopolymers.

Polysaccharide Polymer

The compositions of the present invention may comprise a polysaccharidepolymer.

Typically, the compositions of the present invention may comprise from0.01% to 5%, more preferably from 0.05% to 3% and most preferably from0.05% to 1% by weight of the total composition of a polysaccharidepolymer.

Suitable polysaccharide polymers for use herein include substitutedcellulose materials like carboxymethylcellulose, ethyl cellulose,hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxymethylcellulose, succinoglycan and naturally occurring polysaccharide polymerslike xanthan gum, guar gum, locust bean gum, tragacanth gum orderivatives thereof, or mixtures thereof.

Particularly polysaccharide polymers for use herein are xanthan gum andderivatives thereof. Xanthan gum and derivatives thereof may becommercially available for instance. from Kelco under the trade nameKeltrol RD®, Kelzan S® or Kelzan T®. Other suitable Xanthan gum iscommercially available by Rhone Poulenc under the trade name Rhodopol T®and Rhodigel X747®. Succinoglycan gum for use herein is commerciallyavailable by Rhone Poulenc under the trade name Rheozan®.

Dye

The liquid compositions according to the present invention may becoloured. Accordingly, they may comprise a dye. Suitable dyes for useherein are stable dyes. By “stable”, it is meant herein a compound whichis chemically and physically stable in the acidic environment of thecompositions herein.

Preservative

The compositions according to the present invention may further comprisea preservative as an optional ingredient. Preservatives to be usedherein include all those known to those skilled in the art hohard-surface cleaner compositions. Preservatives are desired hereinbecause they contribute to the stability of the compositions herein.

Suitable preservatives for use herein are diazolidinyl urea, triethylcitrate, propyl 4-hydroxybenzoate, sorbic acid, Na salt ofp-hydroxybenzoate or gluteraldehyde or a mixture thereof.

Radical Scavenger

The compositions of the present invention may comprise a radicalscavenger.

Suitable radical scavengers for use herein include the well-knownsubstituted mono and dihydroxy benzenes and their analogs, alkyl andaryl carboxylates and mixtures thereof. Preferred such radicalscavengers for use herein include di-tert-butyl hydroxy toluene (BHT),hydroquinone, di-tert-butyl hydroquinone, mono-tert-butyl hydroquinone,tert-butyl-hydroxy anysole, benzoic acid, toluic acid, catechol, t-butylcatechol, benzylamine, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, n-propyl-gallate or mixtures thereof and highly preferred isdi-tert-butyl hydroxy toluene. Such radical scavengers likeN-propyl-gallate may be commercially available from Nipa Laboratoriesunder the trade name Nipanox S1®.

Radical scavengers when used, are typically present herein in amounts upto 10% and preferably from 0.001% to 0.5% by weight of the totalcomposition.

The presence of radical scavengers may contribute to the chemicalstability of the compositions of the present invention.

Perfume

The compositions according to the present invention may further comprisea perfume.

Suitable perfumes for use herein include materials which provide anolfactory aesthetic benefit and/or cover any “chemical” odour that theproduct may have. The main function of a small fractions of the highlyvolatile, low boiling (having low boiling points), perfume components inthese perfumes is to improve the fragrance odour of the product itself,rather than impacting on the subsequent odour of the surface beingcleaned. However, some of the less volatile, high boiling perfumeingredients provide a fresh and clean impression to the surfaces, and itis desirable that these ingredients be deposited and present on the drysurface. Perfume ingredients can be readily solubilized in thecompositions, for instance by an anionic detergent surfactant, whenpresent. The perfume ingredients and compositions suitable to be usedherein are the conventional ones known in the art. Selection of anyperfume component, or amount of perfume, is based solely on aestheticconsiderations.

Suitable perfume compounds and compositions can be found in the artincluding U.S. Pat. Nos.: 4,145,184, Brain and Cummins, issued Mar. 20,1979; 4,209,417, Whyte, issued Jun. 24, 1980; 4,515,705, Moeddel, issuedMay 7, 1985; and 4,152,272, Young, issued May 1, 1979, all of saidpatents being incorporated herein by reference. In general, the degreeof substantivity of a perfume is roughly proportional to the percentagesof substantive perfume material used. Relatively substantive perfumescontain at least 1%, preferably at least 10%, substantive perfumematerials. Substantive perfume materials are those odorous compoundsthat deposit on surfaces via the cleaning process and are detectable bypeople with normal olfactory acuity. Such materials typically havevapour pressures lower than that of the average perfume material. Also,they typically have molecular weights of 200 and above, and aredetectable at levels below those of the average perfume material.Perfume ingredients useful herein, along with their odor character, andtheir physical and chemical properties, such as boiling point andmolecular weight, are given in “Perfume and Flavor Chemicals (AromaChemicals),” Steffen Arctander, published by the author, 1969,incorporated herein by reference.

Examples of the highly volatile, low boiling, perfume ingredients are:anethole, benzaldehyde, benzyl acetate, benzyl alcohol, benzyl formate,iso-bornyl acetate, camphene, ciscitral (neral), citronellal,citronellol, citronellyl acetate, paracymene, decanal, dihydrolinalool,dihydromyrcenol, dimethyl phenyl carbinol, eucaliptol, geranial,geraniol, geranyl acetate, geranyl nitrile, cis-3-hexenyl acetate,hydroxycitronellal, d-limonene, linalool, linalool oxide, linalylacetate, linalyl propionate, methyl anthranilate, alpha-methyl ionone,methyl nonyl acetaldehyde, methyl phenyl carbinyl acetate, laevo-menthylacetate, menthone, iso-menthone, mycrene, myrcenyl acetate, myrcenol,nerol, neryl acetate, nonyl acetate, phenyl ethyl alcohol, alpha-pinene,beta-pinene, gamma-terpinene, alpha-terpineol, beta-terpineol, terpinylacetate, and vertenex (para-tertiary-butyl cyclohexyl acetate). Somenatural oils also contain large percentages of highly volatile perfumeingredients. For example, lavandin contains as major components:linalool; linalyl acetate; geraniol; and citronellol. Lemon oil andorange terpenes both contain 95% of d-limonene.

Examples of moderately volatile perfume ingredients are: amyl cinnamicaldehyde, iso-amyl salicylate, beta-caryophyllene, cedrene, cinnamicalcohol, coumarin, dimethyl benzyl carbinyl acetate, ethyl vanillin,eugenol, iso-eugenol, flor acetate, heliotropine, 3cis-hexenylsalicylate, hexyl salicylate, lilial (para-tertiarybutyl-alpha-methylhydrocinnamic aldehyde), gamma-methyl ionone, nerolidol, patchoulialcohol, phenyl hexanol, beta-selinene, trichloromethyl phenyl carbinylacetate, triethyl citrate, vanillin, and veratraldehyde. Cedarwoodterpenes are composed mainly of alpha-cedrene, beta-cedrene, and otherC₁₅H₂₄ sesquiterpenes.

Examples of the less volatile, high boiling, perfume ingredients arebenzophenone, benzyl salicylate, ethylene brassylate, galaxolide(1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-gama-2-benzopyran),hexyl cinnamic aldehyde, lyral (4-(4-hydroxy4-methylpentyl)-3-cyclohexene-10-carboxaldehyde), methyl cedrylone, methyldihydro jasmonate, methyl-beta-naphthyl ketone, musk indanone, muskketone, musk tibetene, and phenylethyl phenyl acetate.

Selection of any particular perfume ingredient is primarily dictated byaesthetic considerations.

The compositions herein may comprise a perfume ingredient, in amounts upto 5.0%, preferably in amounts of 0.1% to 1.5% by weight of the totalcomposition.

Chelating Agent

Another class of optional compounds for use herein includes chelatingagents.

Chelating agents may be incorporated in the compositions herein inamounts ranging up to 10.0%, preferably 0.01%, to 5.0% by weight of thetotal composition.

Suitable phosphonate chelating agents to be used herein may includealkali metal ethane 1-hydroxy diphosphonates (HEDP), alkylene poly(alkylene phosphonate), as well as amino phosphonate compounds,including amino aminotri(methylene phosphonic acid) (ATMP), nitrilotrimethylene phosphonates (NTP), ethylene diamine tetra methylenephosphonates, and diethylene triamine penta methylene phosphonates(DTPMP). The phosphonate compounds may be present either in their acidform or as salts of different cations on some or all of their acidfunctionalities. Preferred phosphonate chelating agents to be usedherein are diethylene triamine penta methylene phosphonate (DTPMP) andethane 1-hydroxy diphosphonate (HEDP). Such phosphonate chelating agentsare commercially available from Monsanto under the trade name DEQUEST®.

Polyfunctionally-substituted aromatic chelating agents may also beuseful in the compositions herein. See U.S. Pat. No. 3,812,044, issuedMay 21, 1974, to Connor et al. Preferred compounds of this type in acidform are dihydroxydisulfobenzenes such as1,2-dihydroxy-3,5-disulfobenzene.

A preferred biodegradable chelating agent for use herein is ethylenediamine N,N′-disuccinic acid, or alkali metal, or alkaline earth,ammonium or substitutes ammonium salts thereof or mixtures thereof.Ethylenediamine N,N′-disuccinic acids, especially the (S,S) isomer, havebeen extensively described in U.S. Pat. No. 4,704,233, Nov. 3, 1987, toHartman and Perkins. Ethylenediamine N,N′-disuccinic acid is, forinstance, commercially available under the tradename ssEDDS® from PalmerResearch Laboratories.

Suitable amino carboxylates to be used herein include ethylene diaminetetra acetates, diethylene triamine pentaacetates, diethylene triaminepentaacetate (DTPA), N-hydroxyethylethylenediamine triacetates,nitrilotri-acetates, ethylenediamine tetrapropionates,triethylenetetraaminehexa-acetates, ethanoldiglycines, propylene diaminetetracetic acid. (PDTA) and methyl glycine di-acetic acid (MGDA), bothin their acid form, or in their alkali metal, ammonium, and substitutedammonium salt forms. Particularly suitable amino carboxylates to be usedherein are diethylene triamine penta acetic acid, propylene diaminetetracetic acid (PDTA) which is, for instance, commercially availablefrom BASF under the trade name Trilon FS® and methyl glycine di-aceticacid (MGDA).

Further carboxylate chelating agents to be used herein include salicylicacid, aspartic acid, glutamic acid, glycine, malonic acid or mixturesthereof.

Bleaches

The liquid compositions herein may also comprise a bleaching component.Any bleach known to those skilled in the art may be suitable to be usedherein including any peroxygen bleach as well as any hypohalite bleach.

Suitable peroxygen bleaches for use herein include hydrogen peroxide orsources thereof. As used herein a source of hydrogen peroxide refers toany compound which produces active oxygen when said compound is incontact with water. Suitable water-soluble sources of hydrogen peroxidefor use herein include percarbonates, preformed percarboxylic acids,persilicates, persulphates, perborates, organic and inorganic peroxidesand/or hydroperoxides.

Suitable hypohalite bleaches for use herein include chlorine releasingcomponents as, e.g., alkali metal hypochlorites. Advantageously, thecompositions according to the present invention are stable in presenceof this bleaching component. Although alkali metal hypochlorites arepreferred, other hypochlorite compounds may also be used herein and,e.g., can be selected from calcium and magnesium hypochlorite. Apreferred alkali metal hypochlorite for use herein is sodiumhypochlorite.

Bleach Activators

In a preferred embodiment wherein the compositions of the presentinvention comprise a peroxygen bleach, said compositions may furthercomprise a bleach activator.

By “bleach activator”, it is meant herein a compound which reacts withperoxygen bleach like hydrogen peroxide to form a peracid. The peracidthus formed constitutes the activated bleach. Suitable bleach activatorsto be used herein include those belonging to the class of esters,amides, imides, or anhydrides.

Examples of suitable compounds of this type are disclosed in BritishPatent GB 1 586 769 and GB 2 143 231 and a method for their formationinto a prilled form is described in European. Published PatentApplication EP-A-62 523. Suitable examples of such compounds to be usedherein are tetracetyl ethylene diamine (TAED), sodium 3,5,5 trimethylhexanoyloxybenzene sulphonate, diperoxy dodecanoic acid as described forinstance in U.S. Pat. No. 4,818,425 and nonylamide of peroxyadipic acidas described for instance in U.S. Pat. No. 4,259,201 andn-nonanoyloxybenzenesulphonate (NOBS). Also suitable are N-acylcaprolactams selected from the group consisting of substituted orunsubstituted benzoyl caprolactam, octanoyl caprolactam, nonanoylcaprolactam, hexanoyl caprolactam, decanoyl caprolactam, undecenoylcaprolactam, formyl caprolactam, acetyl caprolactam, propanoylcaprolactam, butanoyl caprolactam pentanoyl caprolactam or mixturesthereof. A particular family of bleach activators of interest wasdisclosed in EP 624 154, and particularly preferred in that family isacetyl triethyl citrate (ATC). Acetyl triethyl citrate has the advantagethat it is environmental-friendly as it eventually degrades into citricacid and alcohol. Furthermore, acetyl triethyl citrate has a goodhydrolytical stability in the product upon storage and it is anefficient bleach activator. Finally, it provides good building capacityto the composition.

Packaging Form of the Compositions

The compositions herein may be packaged in a variety of suitabledetergent packaging known to those skilled in the art. The liquidcompositions are preferably packaged in conventional detergent plasticbottles.

In one embodiment the compositions herein may be packaged in manually orelectrically operated spray dispensing containers, which are usuallymade of synthetic organic polymeric plastic materials. Accordingly, thepresent invention also encompasses liquid cleaning compositions of theinvention packaged in a spray dispenser, preferably in a trigger spraydispenser or pump spray dispenser.

Indeed, said spray-type dispensers allow to uniformly apply to arelatively large area of a surface to be cleaned the liquid cleaningcompositions suitable for use according to the present invention. Suchspray-type dispensers are particularly suitable to clean verticalsurfaces.

Suitable spray-type dispensers to be used according to the presentinvention include manually operated foam trigger-type dispensers soldfor example by Specialty Packaging Products, Inc. or ContinentalSprayers, Inc. These types of dispensers are disclosed, for instance, inU.S. Pat. No. 4,701,311 to Dunnining et al. and U.S. Pat. No. 4,646,973and U.S. Pat. No. 4,538,745 both to Focarracci. Particularly preferredto be used herein are spray-type dispensers such as T 8500® commerciallyavailable from Continental Spray International or T 8100® commerciallyavailable from Canyon, Northern Ireland. In such a dispenser the liquidcomposition is divided in fine liquid droplets resulting in a spray thatis directed onto the surface to be treated. Indeed, in such a spray-typedispenser the composition contained in the body of said dispenser isdirected through the spray-type dispenser head via energy communicatedto a pumping mechanism by the user as said user activates said pumpingmechanism. More particularly, in said spray-type dispenser head thecomposition is forced against an obstacle, e.g., a grid or a cone or thelike, thereby providing shocks to help atomise the liquid composition,i.e., to help the formation of liquid droplets.

EXAMPLES

These compositions were made comprising the listed ingredients in thelisted proportions (weight %).

Ingredients (% by weight) I II III IV V VI VII VIII IX X XI Dobanol ®1.3 1.5 — 3.5 — — — 2.5 — — 91-8 Isalchem — 1.5 — 3.5 — 1.4 5.0 — — 3.03.0 123 AS ® Lutensol ® — — — — — 1.5 — 2.0 — — — AO 30 n-BPP 2.0 2.02.0 — 2.0 2.0 2.0 — 3.0 5.8 2.0 Benzoic acid 3.5 — — — — 1.5 5.5 — — — —Adipic acid — 2.0 1.0 — — 0.5 — 5.0 — — — Succinic acid — — 1.0 — 1.5 —— — 3.5 2.5 — Telluric acid — — — 1.5 — — — — — — 4.0 Luviskol 0.1 — — 0.05 0.1 — 0.1 — — 0.1 0.1 K60 ® Kelzan T ® 0.3 0.6 — 0.3 — — — 0.3 — —0.3 Waters & - - - up to 100 - - - Minors

The pH of these examples is acidic.

Isalchem 123 AS® is a branched alkyl sulphates commercially availablefrom Enichem.

Kelzan T® is a Xanthan gum supplied by Kelco.

Luviskol K60® is a Polyvinylpyrrolidone supplied by BASF.

n-BPP is butoxy propoxy propanol commercially available from DowChemical.

Dobanol® 91-8 is a C₉-C₁₁ ethoxylated alcohol commercially availablefrom Shell.

Lutensol® AO 30 is a C₁₂₋₁₄ ethoxylated alcohol commercially availablefrom BASF.

All the above compositions are safe to enamel when used to treat enamelsurfaces.

What is claimed is:
 1. A process of cleaning an enamel surface with aliquid acidic composition comprising at least one enamel safe acid, theprocess comprising applying the composition directly to the enamelsurface in either dilute or neat form, wherein the at least one enamelsafe acid has a pK_(a) of 3.5 or higher, wherein the composition is freeof any acid having a pK_(a) of less than 3.5 and free of mono-loweralkyl, phenyl or benzyl ethers of diethylene glycol, wherein the loweralkyl comprises 2 to 6 carbon atoms, and wherein the composition issubstantially free of any source of enamel-damaging cations.
 2. Theprocess according to claim 1 wherein the pK_(a) of the at least oneenamel safe acid is greater than 4.0.
 3. A process according to claim 1wherein said composition comprises from 0.1% to 10% by weight of thetotal composition of said enamel safe acid.
 4. A process according toclaim 1 wherein said composition further comprises a surfactant.
 5. Aprocess according to claim 4 wherein said composition comprises up to15% by weight of the total composition of said surfactant.
 6. A processaccording to claim 1 wherein said composition further comprises asolvent.
 7. A process according to claim 6 wherein said compositioncomprises from 0.1% to 8% by weight of the total composition of saidsolvent.
 8. The process according to claim 1 wherein the pK_(a) of theat least one enamel safe acid is greater than 4.5.
 9. The processaccording to claim 1 wherein the composition has a pH of from 1 to 5.10. The process according to claim 1 wherein the composition has a pH offrom 2 to 4.